Combining polyamide-based resin-molded products and fluororubber into composites is generally performed by a method using an adhesive. However, the adhesion method using an adhesive has problems not only in that the process is complicated, requiring complicated process management and causing high costs, but also in that it is necessary to use large amounts of environmentally hazardous substances, such as organic solvents.
Patent Document 1 discloses a resin-rubber laminate in which a polyamide resin that has been subjected to plasma treatment, corona discharge treatment, or ultraviolet irradiation treatment, and a rubber composition containing an alkoxysilane compound of the following formula:
                R1, R2: any functional groups        R3, R4: hydrocarbon groupsare laminated without interposing an adhesive and bonded. However, although fluororubber is mentioned as an example of the rubber to which an alkoxysilane compound is added, no Examples using fluororubber are provided.        
Patent Document 2 discloses a method for combining a polyamide-based resin-molded product and a member comprising other molding materials into a composite without using an adhesive, wherein at least one of these components is treated with an open air plasma on their contact surface prior to the production of the composite, and the other part is then integrally molded.
Here, vulcanized polymer compounds, such as a fluoropolymer compound, are mentioned as examples of the other molding materials; however, such compounds are molding members (e.g., injection molding member, extrudate, compression molding member), or semifinished products (e.g., single- or multilayer films, textile structures, etc.), and it is not described that the compounds are unvulcanized rubber compounds.
Moreover, Patent Document 3 discloses a fuel hose comprising an inner resin layer and an outer rubber layer laminated on the outer periphery of the inner resin layer, wherein after the inner resin layer made of a polyamide-based resin, fluororesin, or the like is formed by extrusion-molding, and before the outer rubber layer is extrusion-molded, the peripheral surface of the inner resin layer is subjected to microwave plasma treatment under reduced pressure. However, fluororubber is only mentioned as an example of the extrusion molding rubber forming the outer rubber layer.